如何在两个 table 之间建立关系 table? SQL
how to make a relationship table between two table? SQL
我是 SQL 的新手,我正在尝试为研究生和项目建立关系 table。该项目由被称为项目研究助理的研究生负责。我的问题是我收到错误代码:1064,如何解决?我无法确定问题所在。
CREATE TABLE Professor(
Prof_SSN VARCHAR(12),
Prof_Name VARCHAR(12),
Prof_Age VARCHAR(3),
`Rank` VARCHAR(12),
`Research Specialty` VARCHAR(12),
PRIMARY KEY (Prof_SSN)
);
CREATE TABLE `Graduate Students`(
Std_SSN VARCHAR(12),
Std_Name VARCHAR(12),
Std_Age VARCHAR(3),
Degree VARCHAR(12),
PRIMARY KEY (Std_SSN)
);
CREATE TABLE Projects(
`Project number` VARCHAR(10),
`Starting date` VARCHAR(12),
Deadline VARCHAR(8),
Sponsor VARCHAR(12),
Budget VARCHAR(12),
PRIMARY KEY (`Project number`)
);
CREATE TABLE `Project’s Research Assistants`(
Std_SSN VARCHAR(12),
`Project number` VARCHAR(10),
PRIMARY KEY (`Project number`)
FOREIGN KEY (Std_SSN) REFERENCES `Graduate Students`
);```
最后一个 table 创建应该是:
CREATE TABLE `Project’s Research Assistants` (
Std_SSN VARCHAR(12),
`Project number` VARCHAR(10),
PRIMARY KEY (`Project number`)
FOREIGN KEY (Std_SSN) REFERENCES `Graduate Students` (Std_SSN) -- fixed here
);
我是 SQL 的新手,我正在尝试为研究生和项目建立关系 table。该项目由被称为项目研究助理的研究生负责。我的问题是我收到错误代码:1064,如何解决?我无法确定问题所在。
CREATE TABLE Professor(
Prof_SSN VARCHAR(12),
Prof_Name VARCHAR(12),
Prof_Age VARCHAR(3),
`Rank` VARCHAR(12),
`Research Specialty` VARCHAR(12),
PRIMARY KEY (Prof_SSN)
);
CREATE TABLE `Graduate Students`(
Std_SSN VARCHAR(12),
Std_Name VARCHAR(12),
Std_Age VARCHAR(3),
Degree VARCHAR(12),
PRIMARY KEY (Std_SSN)
);
CREATE TABLE Projects(
`Project number` VARCHAR(10),
`Starting date` VARCHAR(12),
Deadline VARCHAR(8),
Sponsor VARCHAR(12),
Budget VARCHAR(12),
PRIMARY KEY (`Project number`)
);
CREATE TABLE `Project’s Research Assistants`(
Std_SSN VARCHAR(12),
`Project number` VARCHAR(10),
PRIMARY KEY (`Project number`)
FOREIGN KEY (Std_SSN) REFERENCES `Graduate Students`
);```
最后一个 table 创建应该是:
CREATE TABLE `Project’s Research Assistants` (
Std_SSN VARCHAR(12),
`Project number` VARCHAR(10),
PRIMARY KEY (`Project number`)
FOREIGN KEY (Std_SSN) REFERENCES `Graduate Students` (Std_SSN) -- fixed here
);